Jerry Wilson Over Coffee Appearing each Wednesday in the Edinburgh Courier, the weekly newspaper in Edinburgh, Indiana and periodically in Indiana's Daily Journal newspaper.

Measuring Things

Quick-how many inches are there in 2.7 yards?

Most people would need a calculator to compute that the answer is 97.2. That’s because the relationship between inches and yards, 36-to-1, is arbitrary and not based on the decimal system.

Now, how many centimeters are there in 2.7 meters? That’s easy; there are 270 of them.

If you know that the relationship between centimeters and meters is 100-to-1, you can quickly do the math in your head by just moving the decimal point. No calculator is necessary.

Notice, too, that the number of centimeters in 2.7 meters is a whole number, whereas the number of inches in 2.7 yards is not.

In 1971, Congress passed a resolution requiring that the U.S. convert to the Metric System within ten years. When it became obvious that not much progress would be made by 1981, the government relented and let us off the hook. But in doing so, it relegated us to being a relic among nations, being the only country in the world to continue to use, as its standard, a traditional and archaic system of measurement.

Oh, we buy pop in two-liter bottles, and anyone who has a computer is certainly familiar with such measures as kilobytes or megahertz. Certainly the medical and scientific communities have converted to metrics entirely. But the population in general still measures things in feet, inches, pounds, ounces, quarts, gallons, and degrees Fahrenheit.

We are all familiar with our traditional system of measurement. That is why we are so reluctant to let go of it. But the metric system, or the International System of Units as it is more properly called now, makes so much more sense.

Not only are conversions much easier to make using metric, as demonstrated above, but also the system itself is actually based upon something. It is not arbitrary.

For example, why is an inch an inch long? Why are there 12 inches in a foot, 3 feet in a yard, and 1,760 yards in a mile? Why does water freeze at 32 degrees F. and boil at 212? And why are there 16 ounces in a pound, unless you mean troy ounces, in which case there are 12? It doesn’t make a lot of sense.

In metrics, for example, the unit of length was originally based on the distance between the North Pole and the Equator. A meter was defined as being one ten-millionth of that distance. In the newer SI system, the meter is basically the same length, but it is actually defined in terms of the speed of light. The meter is now defined as the distance traveled by light in a vacuum in 1/299,792,458 second.

And a second? It is defined as the duration of 9,192,631,770 cycles of the radiation associated with a specified transition, or change in energy level, of the cesium-133 atom.

What actually defines these units is not nearly as important as the relationship between them, and the fact that they are not arbitrary. For instance, once the meter was defined, it was then possible to define a unit of volume using that length. A cube that measures one centimeter on each side becomes one milliliter. A thousand milliliters are in a liter. Also, we can now relate the length and volume measures to weight. One milliliter of water weighs exactly one gram, by definition. So all the measurements are somehow interrelated.

Each metric unit, whether it is length, weight, volume, time, or whatever, can be divided into smaller units or multiplied into larger units by using the same standard prefixes. Kilo- means 1000. Milli-means 1/1000. Centi- means 1/100. Mega- means a million.

So a kilometer is 1000 meters and a kilobyte is 1000 bytes. A millimeter is 1/1000 of a meter and a milliliter is 1/1000 of a liter.

The metric system is so elegantly simple that all the nations of the world have officially switched over to it, except the U.S. We still use the old British system, which even the British no longer use. The old expression, “a pound’s a pound the world ‘round” no longer applies.

The U.S. is the world leader in many areas. Measuring things isn’t one of them.

Copyright © 2001 by Jerry Wilson.